Question

The empirical formula of a compound is CH₂O. Its molecular weight is 90. Calculate the molecular formula of the compound.

Answer 1

the molecular formula
=n×empirical formula
=3×CH2O
=C3H6O3

Answer 2

answer : C3H6O3

explanation : actually, empirical formula is primitive structure of any compound.

so, Molecular formula = n × empirical formula. where n is integer .

here, given,

empirical formula = CH2O

so, weight of empirical formula = atomic weight of C + 2 × atomic weight of H + atomic weight of O

= 12 + 2 × 1 + 16

= 30

and it is given that, molecular weight of compound = 90

so, molecular mass = n × empirical mass

or, 90 = n × 30

or, n = 3

so, molecular formula = 3 × (CH2O)

molecular formula = 3 × (CH2O)= C3H6O3